The thing is, even if one sets the feed rate at 50,000mm/min., it’s something of a moot point since the machine can only accelerate so quickly and move so fast — the thing to really worry about burning up are:
- the brushes in the trim router — don’t run it any faster than you need to
- the tip of the endmill — if it spins in one place too long / removes too little material (it’s the chips which carry away the heat built up by the friction of cutting) it’ll lose its temper and sharpness
With the hobby CNC routers, usually what is done is we try to make up for lack of spindle torque by spinning the endmill faster for inertia to power through cuts, and reduce depth of cut to reduce the cutting forces and the need for torque and the rigidity which is needed to take advantage of it.
We have an entire page of stuff on this:
and no real consensus — the best technique I believe is to:
As I’ve noted in the past, what I really want to see is a physics-based simulation which will take a given material specification and set of toolpaths and then work out the optimal feed rate and spindle speed based on how much material there is to remove at any given point — arguably that’s what the fancy CAM approaches such as trochoidal milling and adaptive clearing are doing.